Estimated human absorbed dose for 68Ga-ECC based on mice data: comparison with 67Ga-ECC

• Published in: Annals of nuclear medicine 2015-07, Vol.29 (6), p.475-481
• Main Authors: Shanehsazzadeh, Saeed, Yousefnia, Hassan, Jalilian, Amir Reza, Zolghadri, Samaneh, Lahooti, Afsaneh
• Format: Article
• Language: English
• Subjects: Imaging; Medicine; Medicine & Public Health; Nuclear Medicine; Original Article; Radiology
• ISSN: 0914-7187; 1864-6433
• DOI: 10.1007/s12149-015-0967-5

Objective Nowadays, the efficacies of 68 Ga-based tracers are comparable to that of 18 F-based agents and have stimulated researchers to investigate the potential of 68 Ga-based positron emission tomography (PET) imaging agents. In this study, the human absorbed dose of 68 Ga labeled with ethylenecysteamine cysteine 68 Ga-ECC and 67 Ga-ECC was estimated based on biodistribution data in mice by the medical internal radiation dose (MIRD) method. Methods For biodistribution of 67 Ga/ 68 Ga-ECC, three mice were killed by CO 2 asphyxiation at each selected times after injection (15, 30, 45, 60, 120 min for 68 Ga-ECC and 0.5, 2 and 48 h for 67 Ga-ECC), and then the tissue (heart, lung, brain, intestine, skin, stomach, kidneys, liver, muscle and bone) was removed. Results 68 Ga-ECC as a new PET renal imaging agent was prepared with radiochemical purity of >97 % in less than 30 min. The biodistribution data for 68 Ga-ECC showed that the most of the activity extracted from the urinary tract very fast. Comparison between human absorbed dose estimation for these two agents indicated that the absorbed dose of the most organs after injection of 67 Ga-ECC is approximately tenfold higher than the amount after 68 Ga-ECC injection. Conclusion The results showed that 68 Ga-ECC is a more appropriate agent rather than 67 Ga-ECC and generally can be a good candidate for PET renal imaging applications.